1. Field of the Invention
The present invention relates to a device for mechanically limiting a rotation range of a rotation body being capable of carrying a device such as a camera and a lighting equipment thereon within a predetermined range of from 360 degrees to 720 degrees.
2. Background of the invention
Conventionally, there has been proposed a turning mechanism or device configured to mechanically limit a rotation range of a rotation body within a predetermined range. For example, see Japanese unexamined Patent Publication JP H7-190162 A (in particular, FIG. 3). As shown in FIGS. 8A-8C, the turning mechanism or device (i.e., a rotation range-limiting device) 100 as disclosed in JP H7-190162 A has a L-shaped block 102 rotatable about a rotation body (i.e., turning shaft) 101, and a block 103 configured to limit a rotation range of the L-shaped block 102. The L-shaped block 102 has a step (a difference in level) on its one side. The turning mechanism or device 100 has a stationary body (i.e. a stationary portion) 104, which rotatably supports the rotation body 101 and is provided with a low stationary block 105 and a high stationary block 106.
Referring to FIG. 8A, the rotation body 101 is rotated in “A” direction. In an extension of the L-shaped block 102 extending toward the stationary body there is provided with a step (a difference in level) which prevents collision against the low block 105. Due to such a step the L-shaped block 102 can pass over the low stationary block 105 and collide against the high stationary block 106. See FIG. 8B. At this time, the block 103 prevents the L-shaped block 102 from turning or rotating in a clockwise direction. As a result, the rotation of the rotation body 101 is blocked or stopped.
Next, when the rotation body 101 is rotated from the position as shown in FIG. 8B in “B” direction, the L-shaped block 102 passes over the low stationary block 105 and collides against the high stationary block 106. Then, the L-shaped block 102 changes its (rotation) direction while rotating. In other words, the L-shaped block 102 then rotates in a counterclockwise direction. Since another extension (i.e., an extension other than the extension extending toward the stationary body) of the L-shaped block 102 has no step (i.e., a difference in level), it collides against the low stationary block 105, thereby inhibiting the rotation of the rotation body 101. This can make mechanically limit the rotatable angle of the rotation body 101 to a predetermined range of from 360 degrees to 720 degrees.
However, as the conventional rotation range-limiting device as disclosed in JP H7-190162 A is provided with the stationary block disposed outside the rotation body, an overall apparatus has a tendency to get bigger. Furthermore, the L-shaped block, the block, and the stationary block are needed, thereby increasing the number of parts to be needed.